For a number of years, all automobile engines and virtually all, if not all internal combustion engines for other applications have been equipped with oil filters. These filters have a finite useful lives and must be changed from time to time to avoid excessive contamination of lubricating oil within an engine. Typically, the spent filter is replaced concurrently with an engine oil change.
When motor oil filters were first introduced, they were typically positioned with the inlet and outlet of the filter oriented upwardly. Such early filters were connected in oil lines communicating with oil passages in the engines and the engine's crank case or connected to the lower portion of the engine's block with an upward orientation. With such upward orientation, it was possible to fill an oil filter with some of the new oil about to be provided for an engine before the filter was connected to that engine.
With many current-day engines, it is no longer possible to prefill the filter before connection to the engine because the filters are oriented with their inlet and outlet openings facing downwardly. Thus, if one attempts to fill the filter with new oil before connecting it to the engine, the oil will pour out as one attempts to connect the filter to the engine.
When an engine is first started up after an oil change, the engine's oil pump and lubricating passages are substantially free of oil because the old oil has been drained from the engine. As such an engine starts the oil pump must self prime and then its output will flow first to the newly installed filter. Until sufficient oil output has been provided to fill the filter, the engine components requiring lubrication will be starved for lubricating oil. A period of the order of 10 to 20 seconds may elapse before oil under pressure is supplied throughout the engine's lubricating system and the wear parts which require lubrication are receiving adequate lubrication. Considerable engine wear can and does occur during this time.
Modern microprocessor controlled ignition systems exacerbate the problem. With a properly tuned microprocessor controlled ignition system, engine start-up is virtually instantaneous as contrasted with several seconds that would pass before even a well tuned engine of the precomputer controlled era would start. This start-up of oil-starved engines has caused a problem. Specifically, excessive engine damage is occurring because oil starvation is occurring.
Investigation has established that service stations which perform oil and filter change services, particularly those of the so-called ten-minute oil change type, are being forced to replace an excessive number of engines which have been severely damaged or destroyed by lack of adequate lubrication on start-up after an oil change. Indeed this investigation suggests auto dismantlers (once known as junkyards) have found a ready market for used engines in selling them to operators of ten-minute oil change facilities. Moreover, the investigation has also revealed that auto manufacturers are experiencing excessive warranty claims.